Automatic welding system for arc-shaped ceiling of large storage tank and control method of automatic welding system

Abstract

The invention relates to an automatic welding system for an arc-shaped ceiling of a large storage tank and a control method of the automatic welding system. The automatic welding system comprises an information collecting and processing module, a path planning and tracking module, a welding robot, a welding seam quality detection module and an intelligent cloud platform; a three-dimensional model of the ceiling is generated; the path planning and tracking module is used for planning a welding path, comparing the welding path with the pose, obtained in real time, of the welding robot and evaluating whether the welding path needs to be adjusted or not; the welding robot is used for automatically welding the ceiling along the welding path; the welding seam quality detection module is used for detecting the quality of a welding seam, automatically marking a position after detecting a defect, generating a repair welding path in combination with the path planning and tracking module, and triggering secondary welding; the intelligent cloud platform is used for controlling the welding robot. The device can adapt to the complex curved surface of the arc-shaped ceiling of the large storage tank, and self-adaption, high-precision welding and intelligent control are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and in particular to an automatic welding system for a curved roof of a large storage tank and a control method thereof. Background Art

[0002] Large storage tanks are widely used in numerous industries, including the petroleum, chemical, and natural gas industries. The quality of the welds on their curved roofs is crucial to the overall performance and safety of the tanks. Traditionally, welding of curved roofs on large storage tanks relies primarily on manual welding, but manual welding presents numerous challenges. For one thing, welding quality is significantly affected by factors such as the welder's skill level, physical condition, and emotional state, making it difficult to ensure consistent welding quality. Furthermore, manual welding is labor-intensive, inefficient, and poses health risks to the welder in harsh working environments.

[0003] With the development of science and technology, automatic welding technology has been gradually applied, which can improve welding efficiency and quality to a certain extent. However, these automatic welding equipment still have shortcomings in adapting to the complex curves of the curved ceiling, self-adaptation, achieving high-precision welding, and intelligent control. For example, in terms of motion trajectory planning and control, the complex curves of the curved ceiling place high demands on the motion trajectory planning and control of the welding robot. Existing welding robots have difficulty in achieving high-precision control when moving along the curved trajectory, which can easily lead to problems such as weld deviation and welding defects. In terms of adaptive adjustment of welding parameters, the thickness and curvature of the curved ceiling vary greatly at different positions, requiring the welding robot to monitor and automatically adjust welding parameters such as welding current, voltage, welding speed, etc. in real time. However, the current welding robots' adaptive capabilities in this regard are not strong enough, and often require manual intervention, which affects the stability of welding efficiency and quality. Summary of the Invention

[0004] The present invention provides an automatic welding system for a large storage tank curved roof and a control method thereof to solve the above technical problems.

[0005] To solve the above technical problems, the present invention provides an automatic welding system for large-scale storage tank curved roofs, including an information acquisition and processing module, a path planning and tracking module, a welding robot, a weld quality detection module, and an intelligent cloud platform.

[0006] The information acquisition and processing module includes a 3D laser scanner and a first camera, which are used to acquire surface information and weld positions of the ceiling and generate a three-dimensional model of the ceiling from the acquired data;

[0007] The path planning and tracking module is used to plan a welding path based on the three-dimensional model, and compare the real-time acquired position and posture of the welding robot with the planned welding path to evaluate whether the welding path needs to be adjusted, and perform correction compensation if adjustment is required;

[0008] The welding robot is used to automatically weld the ceiling along the welding path;

[0009] The weld quality detection module includes an appearance defect detection unit, an internal defect detection unit, and a data processing and pre-analysis unit, which are used to detect weld quality and automatically mark the location after detecting a defect and generate a repair welding path in combination with the path planning and tracking module to trigger secondary welding;

[0010] The intelligent cloud platform includes a terminal device and a communication unit, which are used to control the welding robot.

[0011] Preferably, the path planning and tracking module uses a B-spline curve of an adaptive genetic algorithm to plan the welding path, and divides the ceiling into several sub-areas, independently plans a path for each sub-area, and then connects the paths to the global path.

[0012] Preferably, the welding robot includes a motion control unit, a magnetic-gas hybrid adsorption moving device and a welding assembly, the motion control unit includes a multi-degree-of-freedom robotic arm, and each joint is driven by a reducer and a servo motor; the magnetic-gas hybrid adsorption moving device is used to adsorb the surface of the ceiling; the welding assembly is installed at the end of the motion control unit for performing welding operations on the ceiling.

[0013] Preferably, the magnetic-gas hybrid adsorption moving device includes a magnetic wheel and a vacuum negative pressure chamber, the magnetic wheel is installed on the side of the base, and is used to adsorb the ceiling and move on the ceiling; the vacuum negative pressure chamber is installed under the base.

[0014] Preferably, the welding robot further includes a multimodal welding parameter control unit, which includes a sensor system, a second camera and a TOF laser radar, and is used to identify weld deviations and adjust the welding gun posture.

[0015] Preferably, the sensor system includes at least a current sensor, a voltage sensor, a temperature sensor and a molten pool monitoring sensor for real-time monitoring of parameters during the welding process.

[0016] Preferably, the welding robot further comprises a modular quick-change execution unit, and the modular quick-change execution unit comprises a plurality of flange interfaces, and the plurality of flange interfaces are matched with the welding gun, the gun cleaner and the detection probe respectively.

[0017] Preferably, the modular quick-change execution unit is equipped with a self-cleaning device, which includes a high-pressure air nozzle and a rotating brush.

[0018] Preferably, the appearance defect detection unit adopts a camera; the internal defect detection unit adopts an ultrasonic flaw detector and / or an X-ray imager.

[0019] The present invention also provides a control method for the automatic welding system for the curved roof of a large storage tank as described above, comprising the following steps:

[0020] Step 1: Utilizing the information acquisition and processing module to acquire surface information of the ceiling and establish a three-dimensional model of the ceiling;

[0021] Step 2: The path planning and tracking module plans the welding path according to the three-dimensional model;

[0022] Step 3: The welding robot moves based on the welding path and performs welding operations;

[0023] Step 4: During the welding process, the weld quality detection module monitors the welding operation status and safety conditions in real time, and the intelligent cloud platform adjusts the welding parameters according to the monitoring results.

[0024] Compared with the prior art, the automatic welding system and control method for large storage tank curved roofs provided by the present invention have the following advantages:

[0025] 1. The present invention uses an information acquisition and processing module and a path planning and tracking module to collect the surface topography and weld location of the tank's curved ceiling in real time and plan a path. By acquiring the welding robot's position in real time and comparing it with the planned path, it assesses whether the path needs to be adjusted. If adjustment is required, correction compensation is performed to ensure that the welding robot can travel along the planned path.

[0026] 2. The present invention can not only adapt to the complex curved surfaces of large storage tanks' curved ceilings, but also utilizes the magnetic-gas hybrid adsorption mobile device in the welding robot to make the system highly adaptable, and can still provide adaptive adsorption force when the surface roughness and inclination angle change greatly. In addition, the magnetic-gas dual adsorption mode can ensure that even if a single system fails, it still has a strong adsorption force, thereby improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a system block diagram of an automatic welding system for a large storage tank curved roof in a specific embodiment of the present invention;

[0028] Figure 2 Schematic diagram of the structure of a welding robot in a specific embodiment of the present invention.

[0029] In the figure: 10-base, 20-multi-degree-of-freedom robotic arm, 21-joint, 30-welding component, 41-magnetic wheel, 42-vacuum negative pressure chamber. DETAILED DESCRIPTION

[0030] In order to describe the technical solution of the above invention in more detail, specific embodiments are listed below to demonstrate the technical effects; it should be emphasized that these embodiments are used to illustrate the present invention and are not used to limit the scope of the present invention.

[0031] The present invention provides an automatic welding system and control method for large storage tank curved roofs, such as Figure 1 As shown, it includes information acquisition and processing module, path planning and tracking module, welding robot, weld quality detection module and intelligent cloud platform, among which,

[0032] The information acquisition and processing module includes a high-precision 3D laser scanner and a first camera (multispectral camera), which are used to collect surface information (surface morphology) and weld positions of the curved roof of the tank in real time, and generate a digital three-dimensional model of the roof based on the collected data, and automatically divide the welding area.

[0033] The path planning and tracking module is used to plan the welding path based on the three-dimensional model, and compare the real-time acquired position of the welding robot with the planned welding path to evaluate whether the welding path needs to be adjusted. If adjustment is required, correction compensation is performed so that the welding robot can travel according to the planned path.

[0034] The welding robot is used to automatically weld the ceiling along the welding path.

[0035] The weld quality detection module includes an appearance defect detection unit, an internal defect detection unit, and a data processing and pre-analysis unit, which are used to detect the weld quality. After detecting a defect, it automatically marks the location and combines the path planning and tracking module to generate a repair welding path, triggering secondary welding to ensure welding quality.

[0036] The intelligent cloud platform includes a terminal device and a communication unit for controlling the welding robot. In this embodiment, the intelligent cloud platform includes a remote monitoring and operating system, equipped with a communication unit to realize wireless communication between the welding robot and the control center. The operator can monitor the welding status, parameter settings, work progress and other information of the welding robot in real time through the remote terminal device, and can send operating instructions remotely to adjust the welding parameters and start and stop the welding robot. In other embodiments, the intelligent cloud platform may also include a monitoring unit and a storage unit. The monitoring unit is used to monitor the global status in real time, such as: real-time display of the position, working status (idle, welding, paused, fault), progress percentage, current task information, etc. of all online welding robots. Real-time display of key sensor data (ambient temperature and humidity, wind speed, welding current and voltage, wire feed speed, gas flow, robot posture, weld tracking deviation, etc.). Display a global map of the tank roof, marking the welding robot position and welded / to-be-welded areas. The storage unit is used to store and manage massive amounts of data, such as: structured storage, multi-dimensional query and retrieval of all welding process data (process parameters, sensor data, welding robot trajectory), quality inspection data (visual, ultrasonic and other raw data and results), equipment operation logs, maintenance records, user operation logs, long-term archiving, etc.

[0037] The present invention can adapt to the welding requirements of different parts of the curved roof of a large storage tank and improve the welding efficiency and quality stability.

[0038] In some embodiments, the path planning and tracking module uses an adaptive genetic algorithm (GA) to plan the welding path using B-spline curves, ensuring that the path curvature matches the ceiling curvature by ≥95%. The module also divides the ceiling into several sub-areas, independently planning paths for each sub-area before connecting them to the global path to improve efficiency. In this embodiment, the GA used for path planning optimizes welding time, reduces material waste, and improves weld quality. Using encoders, IMU inertial units, and visual markers, the welding robot's position is acquired in real time and compared with the planned path, significantly improving the adaptability of the automated welding system.

[0039] In some embodiments, please refer to Figure 2The welding robot includes a motion control unit, a magnetic-gas hybrid adsorption mobile device and a welding assembly 30. The motion control unit includes a multi-degree-of-freedom robotic arm 20, and each joint 21 is driven by a precision reducer and a servo motor. It has multiple degrees of freedom and can flexibly reach various welding positions of the curved ceiling within a limited space to meet the welding requirements of different parts of the curved ceiling of large storage tanks; the magnetic-gas hybrid adsorption mobile device is used to adsorb the surface of the ceiling; the welding assembly 30 is installed at the end of the motion control unit and is used to perform welding operations on the ceiling.

[0040] In some embodiments, please refer to Figure 2 The magnetic-gas hybrid adsorption and movement device includes a magnetic wheel 41 with adjustable magnetic force and a plurality of vacuum negative pressure chambers 42. The magnetic wheel 41 is installed on the side of the base 10 and is used to adsorb the ceiling and move on the ceiling. As a moving and adsorption mechanism, it has a fast walking speed and flexible steering. However, because the contact area between its adsorption part and the metal wall is small, the adsorption force and load capacity are weak. The vacuum negative pressure chamber 42 is installed below the base 10. The air pressure inside the chamber is dynamically adjusted by a micro vacuum pump, that is, the air in the suction cup is continuously extracted to form a vacuum negative pressure state, ensuring that the welding robot is stably and firmly adsorbed on the curved ceiling surface after it moves into position. For surfaces with different roughness, the air extraction rate can be adjusted to adjust the adsorption force, so that the adsorption force can be adaptively changed with the surface roughness, ensuring that the welding robot is firmly adsorbed and works stably. During the movement of the welding robot, the vacuum negative pressure chamber 42 detaches from the ceiling surface and is adsorbed on the curved ceiling surface by the magnetic wheel 41 with adjustable magnetic force. In this embodiment, the magnetic wheel 41 adopts a permanent magnet array, and the magnetic attraction force of the permanent magnet array is ≥ 200N / cm 2 The dynamic adjustment range of the air pressure in the vacuum negative pressure chamber 42 is 0.6-0.8 bar, and a three-axis gyroscope and an IMU sensor are configured to compensate for the adsorption force deviation caused by tilt.

[0041] In some embodiments, the magnetic-gas hybrid adsorption movement device further includes a surface inclination sensor, a surface roughness detection unit, and a humidity sensor to collect real-time data on the tank surface inclination, surface roughness, and humidity, and dynamically adjust the air pressure of the vacuum negative pressure chamber 42 using the following formula:

[0042] P adjust =P base ·(1+α·R s +β·H+γ·sinφ)

[0043] Where, P base is the reference air pressure (0.6-0.8 bar), R s is the surface roughness coefficient, H is the relative humidity, φ is the inclination angle of the tank surface, and α, β, and γ are compensation coefficients.

[0044] The magnetic-gas hybrid adsorption mobile device provided in this application has strong adaptability and can still provide adaptive adsorption force when the surface roughness changes greatly and the inclination angle changes greatly; in addition, the magnetic-gas dual adsorption mode can ensure that it still has a large adsorption force when a single system fails, thereby improving safety.

[0045] In some embodiments, the welding assembly may include a welding gun and a wire feeding mechanism. The welding gun may perform welding operations according to instructions sent by a terminal device, and the wire feeding mechanism is used to stably feed welding materials to the welding gun.

[0046] In some embodiments, the welding robot also includes a multimodal welding parameter control unit, which includes a sensor system, a second camera (dual-spectrum camera) and a TOF laser radar. It identifies weld deviations based on the CNN-LSTM fusion algorithm and controls the multi-degree-of-freedom robotic arm 20 to adjust the welding gun posture. The deviation recognition accuracy reaches ±0.1mm.

[0047] In some embodiments, the sensor system includes at least a current sensor, a voltage sensor, a temperature sensor, and a molten pool monitoring sensor, which are used to monitor parameters such as current, voltage, temperature, and weld pool status during the welding process in real time, and transmit the monitoring data to a multimodal welding parameter control unit for analysis and processing. Specifically, the multimodal welding parameter control unit has a built-in material database and environmental sensors, and dynamically adjusts the wire feed speed and welding current through a PID algorithm to adapt to thickness changes at different locations of the curved ceiling, ambient temperature, humidity, and wind speed, and to correct the welding current and voltage parameters in real time. The welding current correction formula is:

[0048] I adj =I base (1-k1·ΔT+k2·v+k3·d)

[0049] Where ΔT is the ambient temperature deviation, v is the real-time wind speed, d is the ceiling thickness, and k1, k2, and k3 are correction coefficients.

[0050] The following problems can be solved by correcting the welding current: 1) It can solve the problem of weld quality fluctuations caused by environmental changes. During high-altitude operations on storage tanks, the ambient temperature (-20℃~50℃) and lateral wind speed (0~15m / s) will change the arc stability, resulting in insufficient penetration or increased spatter; 2) It can solve the weld quality problem caused by the thickness of the material to be welded. The difference in plate thickness in different areas of the curved ceiling requires dynamic matching of the welding current to prevent incomplete fusion or burn-through.

[0051] In some embodiments, the welding robot may further include a modular quick-change execution unit, which includes multiple flange interfaces that comply with the ISO 9409-1 standard. The multiple flange interfaces are respectively matched with welding guns, gun cleaners and detection probes, thereby realizing tool switching within 5 seconds, and is equipped with a dual-station hot-swappable battery compartment to realize rapid battery replacement.

[0052] In some embodiments, the modular quick-change execution unit is also equipped with a self-cleaning device, which includes a high-pressure air nozzle and a rotating brush, which automatically removes rust or impurities on the track contact surface before welding, with a cleaning efficiency of ≥95%. After the welding operation is completed, the welding gun, sensor and other key components are automatically cleaned to remove residual welding slag and impurities, thereby extending the service life and maintenance cycle of the equipment.

[0053] In some embodiments, the modular quick-change execution unit is also equipped with a wireless charging interface, which supports charging the backup battery through electromagnetic induction during the welding process, with a charging efficiency of ≥90%, and the battery compartment has a built-in temperature monitoring module, which automatically switches to the backup battery when the temperature is ≥60°C to ensure safe use.

[0054] In some embodiments, the appearance defect detection unit may use a high-resolution camera to capture images of the weld's appearance, analyze the weld's width, height, shape, and other appearance features based on an image processing algorithm, and determine whether the weld has appearance defects such as undercuts, weld bumps, and dents. The internal defect detection unit may use an ultrasonic flaw detector and / or an X-ray imager to inspect the interior of the weld, capable of detecting defects such as pores, slag inclusions, and cracks within the weld, and determining the location, size, and number of defects. The data processing and analysis unit may integrate and analyze the data collected by the appearance defect detection unit and the internal defect detection unit to generate a comprehensive weld quality assessment report, which includes various weld quality indicator data, defect information, and quality grade assessment results.

[0055] The present invention also provides a control method for the automatic welding system for the curved roof of a large storage tank as described above, comprising the following steps:

[0056] Step 1: Utilizing the information acquisition and processing module to acquire surface information of the ceiling and establish a three-dimensional model of the ceiling;

[0057] Step 2: The path planning and tracking module plans the welding path according to the three-dimensional model;

[0058] Step 3: The welding robot moves based on the welding path and performs welding operations;

[0059] Step 4: During the welding process, the weld quality detection module monitors the welding operation status and safety conditions in real time, and the intelligent cloud platform adjusts the welding parameters according to the monitoring results.

[0060] By adopting the above control method, the welding robot can adapt to complex curved surfaces and achieve high-precision welding and intelligent control.

[0061] In summary, the automatic welding system for the curved ceiling of a large storage tank and its control method provided by the present invention include an information acquisition and processing module, a path planning and tracking module, a welding robot, a weld quality detection module and an intelligent cloud platform. The information acquisition and processing module includes a high-precision 3D laser scanner and a first camera, which are used to collect surface information and weld positions of the curved ceiling of the storage tank in real time, and generate a digital three-dimensional model of the ceiling using the collected data; the path planning and tracking module is used to plan the welding path based on the three-dimensional model, and compare the position of the welding robot acquired in real time with the planned welding path to evaluate whether the welding path needs to be adjusted, and if adjustment is required, perform correction compensation; the welding robot is used to automatically weld the ceiling along the welding path; the weld quality detection module includes an appearance defect detection unit, an internal defect detection unit and a data processing and pre-analysis unit, which are used to detect the weld quality, and after detecting the defect, automatically mark the position and generate a repair welding path in combination with the path planning and tracking module to trigger secondary welding; the intelligent cloud platform includes a terminal device and a communication unit for controlling the welding robot. The present invention can adapt to the welding requirements of different parts of the curved roof of a large storage tank and improve the welding efficiency and quality stability.

[0062] Obviously, those skilled in the art may make various changes and modifications to the invention without departing from the spirit and scope of the invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. An automatic welding system for large storage tank curved roofs, characterized in that: It includes information collection and processing module, path planning and tracking module, welding robot, weld quality detection module and intelligent cloud platform. The information acquisition and processing module includes a 3D laser scanner and a first camera, which are used to acquire surface information and weld positions of the ceiling and generate a three-dimensional model of the ceiling from the acquired data; The path planning and tracking module is used to plan a welding path based on the three-dimensional model, and compare the real-time acquired position and posture of the welding robot with the planned welding path to evaluate whether the welding path needs to be adjusted, and perform correction compensation if adjustment is required; The welding robot is used to automatically weld the ceiling along the welding path; The weld quality detection module includes an appearance defect detection unit, an internal defect detection unit, and a data processing and pre-analysis unit, which are used to detect weld quality and automatically mark the location after detecting a defect and generate a repair welding path in combination with the path planning and tracking module to trigger secondary welding; The intelligent cloud platform includes a terminal device and a communication unit, which are used to control the welding robot.

2. The automatic welding system for large storage tank curved roofs according to claim 1, characterized in that: The path planning and tracking module uses the B-spline curve of the adaptive genetic algorithm to plan the welding path, and divides the ceiling into several sub-areas, independently plans a path for each sub-area, and then connects the global path.

3. The automatic welding system for large storage tank curved roofs according to claim 1, characterized in that: The welding robot includes a motion control unit, a magnetic-gas hybrid adsorption mobile device and a welding assembly. The motion control unit includes a multi-degree-of-freedom robotic arm, and each joint is driven by a reducer and a servo motor; the magnetic-gas hybrid adsorption mobile device is used to adsorb the surface of the ceiling; the welding assembly is installed at the end of the motion control unit and is used to perform welding operations on the ceiling.

4. The automatic welding system for large storage tank curved roofs according to claim 3, characterized in that: The magnetic-gas hybrid adsorption moving device includes a magnetic wheel and a vacuum negative pressure chamber. The magnetic wheel is installed on the side of the base and is used to adsorb the ceiling and move on the ceiling; the vacuum negative pressure chamber is installed under the base.

5. The automatic welding system for the curved roof of a large storage tank as claimed in claim 3, characterized in that: The welding robot also includes a multimodal welding parameter control unit, which includes a sensor system, a second camera and a TOF laser radar, and is used to identify weld deviations and adjust the welding gun posture.

6. The automatic welding system for large storage tank curved roofs according to claim 5, characterized in that: The sensor system includes at least a current sensor, a voltage sensor, a temperature sensor and a molten pool monitoring sensor, which are used to monitor parameters during the welding process in real time.

7. The automatic welding system for large storage tank curved roofs according to claim 5, characterized in that: The welding robot further comprises a modular quick-change execution unit, which comprises a plurality of flange interfaces, and the plurality of flange interfaces are matched with the welding gun, the gun cleaner and the detection probe respectively.

8. The automatic welding system for large storage tank curved roofs according to claim 7, characterized in that: The modular quick-change execution unit is equipped with a self-cleaning device, which includes a high-pressure air nozzle and a rotating brush.

9. The automatic welding system for large storage tank curved roofs according to claim 1, characterized in that: The appearance defect detection unit adopts a camera; the internal defect detection unit adopts an ultrasonic flaw detector and / or an X-ray imager.

10. A control method for an automatic welding system for a large storage tank curved roof according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: Utilizing the information acquisition and processing module to acquire surface information of the ceiling and establish a three-dimensional model of the ceiling; Step 2: The path planning and tracking module plans the welding path according to the three-dimensional model; Step 3: The welding robot moves based on the welding path and performs welding operations; Step 4: During the welding process, the weld quality detection module monitors the welding operation status and safety conditions in real time, and the intelligent cloud platform adjusts the welding parameters according to the monitoring results.

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